The European lobster (Homarus gammarus) is an ecologically important species of the North-eastern Atlantic which supports wild trap fisheries that are worth around £30 million each year to the UK alone. By weight the species is the highest-value seafood among those landed regularly in the UK and Ireland, where 75 percent of the ~5,000t annual landings for the species are made. As such, lobsters provide essential diversity to fragile inshore fisheries and vital income for rural coastal economies. However, populations across its range are pressured by rising exploitation, from which traditional fisheries management has failed to prevent extensive regional stock collapses in the recent past, and now struggles to stimulate recovery. While lobsters have long been transported as a live export commodity, chiefly to France and the Iberian peninsula, emerging markets, particularly those in East Asia, threaten to create additional demand for the species which far exceeds current capture yields. Improvements in hatchery rearing success have seen a number of recent aquaculture initiatives employed, in the hope of both generating restoration and improved sustainability of wild harvests, and instigating commercial aquaculture possibilities.

1. POTENTIAL FOR
EUROPEAN LOBSTER
MARICULTURE
by, Dr Carly Daniels and Charlie Ellis,
The National Lobster Hatchery, Padstow, UK
Photo: Dr Carly Daniels, Research and Development
Officer at the National Lobster Hatchery, holds a
juvenile European lobster reared in a sea-based
container culture system in Cornwall, UK
18 | May | June 2016 - International Aquafeed
FEATURE

2. T
he European lobster (Homarus
gammarus) is an ecologically important
species of the North-eastern Atlantic
which supports wild trap fisheries that
are worth around £30 million each
year to the UK alone. By weight the
species is the highest-value seafood
among those landed regularly in the
UK and Ireland, where 75 percent of
the ~5,000t annual landings for the species are made. As such,
lobsters provide essential diversity to fragile inshore fisheries and
vital income for rural coastal economies. However, populations
across its range are pressured by rising exploitation, from which
traditional fisheries management has failed to prevent extensive
regional stock collapses in the recent past, and now struggles to
stimulate recovery. While lobsters have long been transported
as a live export commodity, chiefly to France and the Iberian
peninsula, emerging markets, particularly those in East Asia,
threaten to create additional demand for the species which
far exceeds current capture yields. Improvements in hatchery
rearing success have seen a number
of recent aquaculture initiatives
employed, in the hope of both
generating restoration and improved
sustainability of wild harvests, and
instigating commercial aquaculture
possibilities.
Of the three major aquaculture
practices –resource enhancement,
product enhancement, and full
grow-out – the majority of hatchery
culture of H. gammarus has been
applied via resource enhancement,
the improvement of wild capture
harvests via the release of hatchery-
reared juveniles (‘hatchery
stocking’, including both restocking
and stock enhancement). These
strategies should be well suited to
H. gammarus, a high-value, fecund
species with planktonic early
life-stages which are presumed to be subject to considerable
recruitment bottlenecks in nature, and monitored trials have
demonstrated a proof-of-principle of hatchery stocking.
Having been reared from the clutches of wild-mated females,
considerable numbers of released lobsters have been recovered
in the wild, having survived, attained maturity, and mated
successfully across multiple locations and ecotypes across a
broad section of the species’ range, although direct economic
viability of the approach is still to be rigorously assessed.
Product enhancement, the captive on-growth of wild-captured
stock to improve marketability, as is practice in Tuna aquaculture,
is at present prevented in European Lobster by a lack of necessity
combined with of our enduring inability to locate wild H.
gammarus juveniles and strict fishery minimum landing sizes.
Technological progress has raised the possibility that full-
grow out aquaculture may soon attain commercial applications.
Encouraging developments in recent years have seen the captive
culture of European lobster to marketable sizes in Norway, whose
own wild fishery was decimated by stock collapse in the middle
of the twentieth century. Considerable complications arise from
the species’ slow growth rate and willingness to cannibalise when
confined communally in captivity, but significant potential has
been identified in the mariculture of hatchery-reared juveniles in
containers moored at sea. Sea-based container culture (SBCC)
avoids many of the rearing costs associated with aquaria-based
operations, and is currently the focus of research aiming to
enhance the effectiveness of stocking programs and initiate a
novel mariculture sector.
The National Lobster Hatchery
As global demand for seafood grows, we require a more
thorough understanding of methods designed to enhance the
abundance of high value species, restore depleted fisheries,
and build resilience and sustainability into seafood supply.
The work of the National Lobster Hatchery (NLH) in Padstow,
UK, focusses upon these pressing issues. The NLH is a charity
focussing on conservation, education and research, established
in 2000 with the goal of undertaking stock enhancement to help
support the sustainability of the local H. gammarus fishery.
Recent years have seen substantial advances in the charity’s
outputs, with over 150,000 juvenile lobsters admixed into local
stocks around the coasts of Cornwall and the nearby Isles of
Scilly since 2009. A harbour side visitor centre, from which
visitors can view the hatchery rearing process, routinely attracts
over 43,000 people per year, and has been complemented in
recent years by an outreach programme that visits schools,
universities and community groups to introduce seafood
conservation issues and highlight the need for sustainable
fisheries and aquaculture.
The project also supports a specialist research team, who have
helped further our understanding of wild lobster biology via a
range of ecological studies, as well as providing biotechnical
advances to improve and stabilise hatchery production. The NLH
is a founding member of ELCE – the European Lobster Centre
of Excellence – a network of specialists in lobster biology and
culture who collaborate in research and meet to share knowledge
and experiences to further the shared goals of developing lobster
conservation, stocking and aquaculture programmes. The NLH
research team is now attracting national and international
recognition for its work tackling some of the remaining barriers
to the development of clawed lobster aquaculture.
The Lobster-Grower projects
The NLH has spent a proportion of the past the past six years
investigating the potential for rearing lobsters at sea in container
systems, following initial success with clawed lobsters across
Lobsters share their rearing
containers with a diverse
community of organisms which
settle around them and provide
plentiful food. Self-seeded scallops
readily co-habit with lobsters,
raising the prospect of multi-species
shellfish culture.
International Aquafeed - May | June 2016 | 19
FEATURE

3. costs, no immediate need for valuable seafront buildings,
and even no requirement for processed feed; the lobsters
are thought to initially feed on planktonic organisms before
subsisting on animals and algae which settle on and encrust
the container. Some trials have suggested that growth and
survival rates in SBCC can exceed those attained in hatchery
on-growing vessels, despite SBCC lobsters experiencing lower
average temperatures. Rearing lobsters at sea also appears
to promote natural behaviours, and traits that are likely to be
important to wild survival. The performance of maricultured
lobsters in these trials raises hopes that the SBCC method
could provide a dual opportunity to develop sustainability
and resilience in the lobster supply chain; as well as raising
the possibility of initiating aquaculture applications, rearing
at sea may well fulfil an important role in the ecological
conditioning of hatchery lobsters destined for wild release.
Although hatchery lobsters innately develop some behaviours
which are critical to their post-release survival, settlement
success is enhanced by adaptation to the natural environment,
and the comparatively enriched semi-wild SBCC environment
appears to promote attributes which are likely to enhance the
effectiveness of stock enhancement and restocking schemes,
increasing their overall benefit to fishery recruitment.
As well as supporting the development of juvenile lobsters,
SBCC systems provide an ideal settlement environment for a
variety of other valuable shellfish species, including mussels
and scallops, inviting the prospect that they could support
multi-species coastal mariculture operations of considerable
value and exceptional sustainability credentials. While no
lobsters have yet been reared to current fisheries landing sizes
in SBCC systems, there may be considerable appetite among
consumers and luxury seafood suppliers for lobsters which are
slightly smaller than those currently accessible to the fishery.
The realisation of commercial-scale lobster mariculture
could facilitate this market diversification and help to offset
pressure on dwindling natural stocks, and the NLH hopes to
be at the forefront of efforts to conserve both the species’ wild
populations and the livelihoods of coastal communities who
target them.
several countries during the previous decade. In 2014, the NLH
engaged a diverse consortium of expert partners to assist in
the development of the equipment and techniques required to
pioneer and evaluate the mariculture of hatchery-reared lobster
juveniles. This project, named ‘Lobster Grower’ and jointly
funded by Innovate UK and the Biotechnology and Biological
Sciences Research Council (BBSRC), designed and lab
tested bespoke containers compatible with the developmental
requirements of lobsters and integration into existing UK
mariculture operations, a step further on from previous trials
which focussed on the use of oyster spat containers.
A follow-up project, Lobster Grower 2, has now been
awarded by the same funders, allowing the diverse set of
partners to field-test these bespoke containers. Alongside
the NLH, the University of Exeter, Westcountry Mussels of
Fowey (WMoF), the Centre for Environment, Fisheries and
Aquaculture Science (CEFAS) and Falmouth University
will be investigating the performance of these novel
rearing containers to support semi-intensive lobster culture
in the ocean environment. Over the next three years the
consortium will be assisting WMoF to rear lobsters alongside
their existing rope-grown bivalve culture operations, and
developing and testing novel systems for securing containers.
An extensive environmental monitoring program will help
reveal the influence of environmental conditions on the growth
and survival of lobsters, as well as detecting any impacts of
lobster culture on the surrounding ecosystem. Biological,
ecological and hydrodynamic data arising from the project
will be combined with information on social, operational and
financial requirements to create an aqua-economic model
which will be available to potential industry start-ups to help
predict production and economic returns.
Benefits of Sea Based Container Culture
SBCC has significant advantages over recirculation-based
rearing methods, which are often associated with high capital
and operational costs, including: having no continuous energy
Dr Carly Daniels, Research
and Development Officer
at the National Lobster
Hatchery, deploys a
mature stack of rearing
containers in Cornwall, UK,
under the watchful eye
of Mr Gary Rawle, who is
hosting the lobster rearing
trials at his Westcountry
Mussels of Fowey shellfish
farm.
20 | May | June 2016 - International Aquafeed
FEATURE

4. Complete Plants and Machines
for the Production of Fish Feed
Contrary to conventional extruders, the KAHL extruder OEE is equipped
with a hydraulically adjustable die.
AMANDUS KAHL GmbH & Co. KG · Dieselstrasse 5-9 · D-21465 Reinbek / Hamburg · Phone: +49 40 727 71 0
info@akahl.de · www.akahl.de
International Aquafeed - May | June 2016 | 21
FEATURE